_Records of occurrence._--Specimens examined, 15: Rancho Pano Ayuctle, 6 mi. N Gómez Farías, 300 ft., 13; cave at headwaters of Río Sabinas, 10 km. N, 8 km. W El Encino, 400 ft., 2. =Artibeus toltecus= (Saussure) Toltec Fruit-eating Bat 1860. _Stenoderma toltecus_ Saussure, Revue et Mag. Zool., Paris, ser. 2, 12:427, October, type from México. Type locality restricted to Mirador, Veracruz, by Hershkovitz, Proc. U. S. Nat. Mus., 99:449, May 10, 1949. 1908. _Artibeus toltecus_, Andersen, Proc. Zool. Soc. London, p. 296, April 7. _Distribution in Tamaulipas._--Probably lowlands of southern part of state; known presently only from Rancho Pano Ayuctle. _Artibeus toltecus_ is closely related to another species, _A. aztecus_, that occurs also in Tamaulipas. Externally, _toltecus_ differs from _aztecus_ in being smaller and darker; cranially, _toltecus_ also is the smaller and the P2 and M2 are more angular lingually than in _aztecus_, in which the teeth are rounded. One of the most important differences between these two species is that they occur at different altitudes. Davis (1958:165) reported that _toltecus_ occurred at elevations below 5000 feet at more southerly localities in México, whereas _aztecus_ occurred above 5000 feet. In Tamaulipas the two species probably have parallel distributions from south to north but _A. toltecus_ is known from Rancho Pano Ayuctle at an elevation of 300 feet in rain forest, whereas _A. aztecus_ is known from Rancho del Cielo at an elevation of 3300 feet in cloud forest. The two localities are only four miles apart. One of the specimens examined (GMS 10640) is smaller, cranially and externally (see beyond), than any recorded by Davis (1958:165). _Measurements._--Some external and cranial measurements of two females and a male (GMS 10668, 10646 and 10640) are, respectively, as follows: length of hind foot, 12.5, 12.0, 11.0; length of ear from notch, 15, 17, 15; length of forearm, 40.5, 40.0, 36.5; greatest length of skull, 20.9, 20.7, 19.7; zygomatic breadth, 12.3, 12.3, 11.7; least interorbital constriction, 5.2, 5.0, 5.0; length of maxillary tooth-row, 6.8, 6.8, 6.5; breadth of braincase, 9.3, 9.2, 9.1. _Records of occurrence._--Specimens examined, 3 from Río Sabinas, near Gómez Farías (Rancho Pano Ayuctle) (GMS). =Artibeus aztecus= Andersen Aztec Fruit-eating Bat 1906. _Artibeus aztecus_ Andersen, Ann. Mag. Nat. Hist., ser. 7, 18:422, December, type from Tetela del Volcán, Morelos. _Distribution in Tamaulipas._--Probably higher areas of southern part of state; known presently only from Rancho del Cielo. I follow Davis (1958:165) in treating _A. aztecus_ and _A. toltecus_ as distinct species. Differences between the two are discussed in the preceding account of _toltecus_.